Lubricating oil thickened to a grease consistency with a mixture of a tetraphenylphthalyl compound and an organophilic siliceous compound



are represented by the formula:

2,983,682 LUBRICATING OIL THICKENED TO A GREASE CONSISTENCY WITH AMIXTURE OF A TETRA- PHENYLPHTHALYL COMPOUND AND AN R- GANOPHILICSILICEOUS COMPOUND Robert E. Halter, Verona, and Joseph J. McGrath,Monroeville, Pa., assignors to Gulf Research & Development Company,Pittsburgh, Pa., a corporation of Delaware k No Drawing. Filed July 10,1959, Ser. No. 826,143 r 14 Claims. (Cl. 252-495) invention relates toimproved lubricating compositions and more particularly to lubricantssuitable for high temperature lubrication.

The trend in design of modern aircraft has accentuated the needforgreases which willlubricate anti-friction United States PatcntO icebearings operating at high rotational speeds and high temperatures.While considerable progress has been made in recent years in producingimproved aircraft greases somedifiiculty has been encountered inproducing a grease which will efiectively lubricate bearingsopcrating-lat high rotational speeds and high temperatures for prolongedperiods of time. Conventional aircraft greases currently available havefailed to meet the stringent requirements on such a lubricant.

We have discovered that a lubricating composition having improvedlubricating characteristics for an extended period of time when used tolubricate bearings operating at anelevated temperature under highrotational speeds can be obtained by incorporating into a lubricatingoil in oil thickening proportions a mixture of a tetraphenylphthalylcompound selected from the group consisting of tetraphenylphthalic acidand derivatives thereof selected from the group consisting of theanhydride, monoand di-alkali metal salts, monoand di-amides,

alkali metal salts of mono-amides, monoesters, alkali metal salts ofmonoesters, and im-ides and a secondary organcphiiic siliceousthickening agent. Thus, the im-,

proved lubricatingcomposition of our invention com- :prises .adispersion in a lubricating oil of a sufficient amount to thicken thelubricating oil to a grease con- 2,983,682 Patented May 9, 1961 where Ais selected from the group consisting of OR, OM and NRRQ'Where M is analkali metal and R and R are selected from the group consisting of H andaliphatic, alicyclic and aromatic hydrocarbon radicals having from 1 to22 carbon atoms.

Examples of R and R as aliphatic, alicyclic and arc matic hydrocarbonradicals include methyl, ethyl, propyl, n-butyl, tertiary butyl, pentyl,cyclopentyl, hexy, 2,3-dimethylbutyl, cyclohexyl, heptyl, 2-ethylhexyl,isooctyl, n-octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl,octadecyl, eicosyl, docosyl, phenyl, naphthyl, and the like.

Specific examples of some of the tetraphenylphthalamates are:

N-methyl tetraphenylphthalamate N,N-d-irnethyl tetraphenylphthalamateN-butyl tetraphenylphthalamate N,N-ditertiary-butyltetraphenylphthalamate N-cyclohexyl tetraphenylphthalamateN,N-dicyclohexyl tetraphenylphthalamate N-isooctyltetraphenylphthalamate N,N-diisooctyl tetraphenylphthalamate N-octadecyltetraphenylphthalamate N-eicosyl tetraphenylphthalamate N-docosyltetraphenylphthalamate N-phenyl tetraphenylphthalamate N,N-diphenyltetraphenylphthalamate N-naphthyl tetraphenylphthalamate Sodium N-methyltetraphenylphthalamate Potassium N,N-dimethyl tetraphenylphthalamateLithium N-butyl tetraphenylphthalamate Sodium N,N-ditertiary-butyltetraphenylphthalamate Potassium N-cyclohexyl tetraphenylphthalamate ILithium N,N-dicyclohexyl tetraphenylphthalamate sistency of a mixture ofa tetraphenylphthalyl compound of the type designated above and anorganophilic siliceous oil thickening agent.

U ,The amount of the combined tetraphenylphthalyl compound and theorganophilic siliceous material which we use is an amount sufiicient tothicken the lubricating oil to a grease consistency. In general, thisamount comprises about 10 to about 60 percent by Weight of the L totalcomposition. The Weight ratio of the tetraphenylphthal-yl compound tothe organophilic siliceous material will vary depending upon thecharacteristics desired in the ultimate composition. in general,however, the ratio of tetraphenylphthalyl compound to the organophilicsiliceous materialis between about 1:1 and about :1.

The tetraphenylphthalyl compounds which We can employ includetetraphenylphthalic. acid, tetraphenylphthalic anhydr ied, monoanddi-sodium tetraphenylphthalates,

mono and iii-potassium tetraphenylphthalates, monoand di-lithiumtetraphenylphthalates, monoand di-tetraphenylphthalamates, alkali metalsalts of mono-tetraphenylphthalamates, monoesters of tetraphenylphthalicacid, alkali metal salts of monoesters of tetraphenylphthalic acid and,tetraphenylphthalimides. l

l The -monoand di-tetraphenylphthalamates and the alkali metal salts ofthe mono-tetraphenylphthalamates Octadecyl N-butyltetraphenylphthalamate Eicosyl N-butyl tetraphenylphthalamate Themonoesters of tetraphenylphthalic acid and the alkali metal salts of themonoesters of tetraphenylphthalic acid are represented by the formula:

. 1 3 lected from the group consisting of aliphatic, alicyclic andaromatic hydrocarbon radicals having from 1 to 22 carbon atoms. Specificexamples of some of the monoesters of tetraphenylphthalic acid and thealkali metal salts of the monoesters of tetraphenylphthalic acid are:

Mono-methyl tetraphenylphthalate Mono-n-butyl tetraphenylphthalateMono-tertiary-butyl tetraphenylphthalate The imides oftetraphenylphthalic acid are represented by the formula:

where R is selected from the group consisting of hydrogen and aliphatic,alicyclic and aromatic radicals having from 1 to 22' carbon atoms.

Specific examples of some of the imides of tetraphenylphthalic acid are:i

N-methyl tetraphenylphthalimide N-ethyl tetraphenylphthalimide N-propyltetraphenylphthalimide N-butyl tetraphenylphthalimide N-cyclohexyltetraphenylphthalimide N-octyl tetraphenylphthalimide N-decyltetraphenylphthalimide N-dodecyl tetraphenylphthalirnide N-tetradecyltetraphenylphthalimide N-hexadecyl tetraphenylphthalimide N-octadecyltetraphenylphthalimide N-eicosyl tetraphenylphthalimide N-docosyltetraphenylphthalimide N-phenyl tetraphenylphthalimide ,N naphthyltetraphenylphthalimide 57? The amount of thetetraphenylphthalyl'compiund used may vary over wide limits dependingupon the particular oil with which the tetraphenylphthalyl compound isto be blended and upon the proper-ties desired in the final lubricatingcomposition. While as much as 50 percent by weight of the totalcomposition may comprise .the

tetraphenylphthal-yl compound, weprefer to use smaller removed bydistillation at 92-94? 0/20 mm. The re'sidue after tworecrystallizations from carbon tetrachloride,

amounts, that is, in the order of about 10 to 40 percent 6 "-5 should beunderstood, however, that, depending upon the consistency of .thecomposition desired and upon the organophilic siliceous material used incombination therewith, less than 10 percent or more than 50 percent ofthe tetraphenylphthalyl compound may be employed.

' The tetraphenylphthalyl compounds "can 'be prepared according to knownchemical procedures. Neither the compounds per se nor their preparationconstitutes any portion of the invention. The preparation oftetraphenylphthalic anhydride, for example, can be prepared according toa procedure described in the Journal of the American Chemical Society,volume 67, page 1229, (1945). The alkali metal salts, the amides, theesters and the imides can be prepared according to known salt-forming,amidation, esterification and imidation procedures, respectively. Thefollowing illustrative examples will serveto demonstrate the preparationof some of the specific tetraphenylphthalyl compounds. The utility ofthese tetraphenylphthalyl compounds informing lubricating compositionsof the invention is illustrated by the data presented in Table I.

EXAMPLE 1 (Tetraphenylphthalic anhydride) i A mixture of 384 gm. (1mole) of tetraphenylcyclopentadienone and 146 gm. (1.1 mole)chloromaleic an hydride was refluxed for 4 hours. The mixture was cooledto 0 C. and filtered. The crystals of tetra- :phenylphthalic anhydrideWere first washed with asmall amount of cold bromobenzene and finallywith petroleum ether (B.P. 60-70 C.). The melting point of thetetraphenylphthalic anhydn'de crystals was 294296 C.

EXAMPLE 2 (Disoa'ium tetraphenylphthalate) e To 124 g. oftetraphenylphthalic anhydride in suflicient 95% ethanol to give a slurrywas added 3140 ml. of 0.35 N alcoholic sodium hydroxide. This mixturewas heated at reflux temperature for sixteen hours, cooled and filtered.The filtrate was heated to boiling and diluted with hot water untilcrystallization occurred,

cooled to 0 C. and filtered. The product, disodium tetraphenylphthalate,after drying at C. melted above 400 C. (752 F.).

EXAMPLE 3 (Methyl N-n-octadecylletrapherzylphthalamate) Phosphorustrichloride (10.4 gm., 0.076 mole) was added dropwise to a stirredsuspension of 79.3 gm. (0.152

'mole) of potassium methyl tetraphenylphthalate and 819 gm. (0.304 mole)of moctadecylamine in ml.

of toluene in a Morton flask. During the addition the "temperature rosefrom 24 C. to 55 C. An additional 100 ml. of toluene was added tocounteract solidification.

The mixture was heated at reflux for thirty hours afterdecyltetraphenylphthalamate, a solid, melting at SS-{85 (Mono-isooctylietraphenylphthallate) Ten grams (0.021 mole) of tetraphenylphthalicanhydride and 46 gm. (0.2 mole) isooctyl alcohol'wererefluxed for 2hours. The unreacted isooctyl alcohol was comprising mono-isooctyltetraphenylphthalate had a melting point of 294;295 C. i

phthalic anhydride and 20.4 gm. (0.2 mole) of n-hexanol was refluxed for1.5 hours. The excess alcohol was removed by distillation at 100 C./25mm. The residue after two. crystallizations from carbon tetrachloridegave a product, mono-n-hexyl tetraphenylphthalate, melting at 295-296 C.

The organophilic siliceous materials which we employ in the lubricatingcomposition of this invention are exemplified by bentonite organic basecompounds known commercially as Bentones and finely dividedorganosiliceous solids such as the esterified siliceous solids knowncommercially as Estersils. The amount of the organophilic siliceousmaterial employed may vary over .wide limits depending upon theparticular compound employed, the particular oil with which thesiliceous compound is blended and the properties desired in the ultimatecomposition. While the organophilic siliceous material may comprise asmuch as 20 percent by weight of the total composition, we prefer to usesmaller amounts, that is, in the order of about 1 to about percent byweight. It should be understood, however, that depending upon theconsistency of the composition desired and upon the tetraphenylphthalylcompound content of the composition less than 1 percent or morethan 10percent of the organophilic siliceous material can be employed.

fTypical bentonite-organic base compounds employed in accordance withtheinvention are compounds composed of a montmorillonite mineral in whichat least a part of the cation content of the mineral has been replacedby an organic base.

Clays that swell at least to some extent on being contacted with waterand contain as a primary constituent a mineral of the group known (Thebentonite-organic base compounds are. preferably prepared as describedin US. Patent No. 2,033,856, is-

sued March 10, 1936 by bringing together the bentonite and the organicbase in the presence of aqueous mineral acid to effect base exchange.The organic bases should preferably be titratable with mineral acids.Among these .reactive bases are many alkaloids, and cyclic, aliphatic,and heterocyclic amines. The bentonite-organic base compounds used inpreparing the lubricating compositions of this invention are preferablythese. prepared by bringing together a bentonite clay and such organicbases "asaIiphatic amines, their salts, and quaternary ammoriium salts.Examples of such amines and salts are:

jdecylamine, dodecylamine, tetradecylamine, hexadecylamine,octadecylamine, hexadecyl ammonium acetate,

octadecyl ammonium acetate, .dirnethyldioctyl ammoniumacetate,,dimethyldidodecyl ammonium acetate, di-

fm ethyldodecylhexadecyl ammonium acetate, dimethyldicetyl ammoniumacetate, dimethylhexadecylocta'decyl ammonium acetate,dimethyldioctadecyl ammonium ace tate, and the corresponding chloridesand quaternary ammonium chlorides. fThe organic bases employed should besuch as to impart substantial organophilic The preferred ammoniumcompounds in which the N-substituents are aliphatic groupsjcontaining"at least one alkylj group "witha total of at least 10 to 12carbon atoms. When aliphatic amines are used they preferably'contaiii.at least bentonite compounds, in the oil, particularly mineral oils andsynthetic oils other than ester lubricants, can be facilitated by theuse of one or more solvating agents. Suitable solvating agents are polarorganic compounds such as organic acids, esters, alcohols, ethers,ketones, and aldehydes, especially low molecular weightcompounds ofthese classes. Examples of suitable solvating agents are: ethyl acetate,acetic acid, acetone, methyl alcohol, ethyl alcohol, benzoylchloride,butyl stearate, cocoanut oil, cyclohexanonejethylene dichloride, ethylether, furfural, isoamyl acetate, methyl ethyl ketone, and nitrobenzene.In cases where the use of'a solvating agent is desirable for efiectingmore rapid and more complete dispersion of the organic bentonitecompound in the oil, ordinarily only a relatively small amount of suchagent may be necessary. However, as much as about 50 percent by weightbased on the amount of the bentonite compound can be used.

' Typical estersils employed in accordance with the invention aredescribed in US. Patent No. 2,657,149, issued October 27, 1953 to R. K.Iler. The estersils are organophilic solids made by chemically reactingprimary or secondary alcohols with certain siliceous solids. In brief,the estersils are prowders or pulverulent materialsthe internalstructure or substrate of which have a bound organic groups prior toesterification. Thesubstrates are in a supercolloidal state ofsubdivision, indicating that whatever discrete particles are present arelarger than colloidal size. In general, the supercolloidal substrateshave at least one dimension of at least 150 millimicrons. Thesupercolloidal particles may be aggregates of ultimate units which arecolloidal in size.

The estersils which we employ are advantageously those in which theultimate units have an average diameter of 8 to 10 millimicrons. Thesubstrates advantageously have specific surface areas of at least 25square meters per gram and preferably at least 200 square meters pergram.

The estersils made from most alcohols become organophilic when theycontain more than about 80.ester groups per 100 square millimicrons ofsurface of internal structure." They become more organophilic as theester groups increase. Thus, the products which contain 100 ester groupsper '100 square millirnicrons of substrate surface are more organophilicthan those that contain only ester groups. When the estersils contain atleast 200 ester groups per square r nillimicrons of substrate surface,the estersils not only are organophilic but also are hydro phobic. Thus,the more highly esterified products are particularly desirable where thelubricant made therefrom comesin contact-With water. When C to Calcohols are used in preparing the estersils, the estersils may containfroin 300 to 400 ester groups per 100 square milliriiicronsof substratesurface. Thus, a preferred group of estersils are those prepared-fromthe C to C alcohols. The'estersils, asnotedabove, are powders orpulverulent, materials. ,lThe, estersil. powders are exceedingly fine,

light and The bulk densityb'f preferred estersils .isin the'order of to0.20 gram percufbic. centimeter a't 3 pounds per square inch and in theorder of about .the estersils per se and their ;we r'nean an oil ofnon-mineral origin. .oil can be an organic ester which has a majority ofthe 0.30 gram per cubic centimeter at 78 pounds per square rated ispreferably a lubricant of the type best suited for the particular usefor which the ultimatecomposition is the lubricating oil are imparted tothe ultimate lubricating composition, we'advantageously employ an oilwhich is .thermally stable at the contemplatedlubricating temperature.Some mineral oils, especially hydrotreated mineral oils, aresufliciently stable to provide a lubricating base for preparinglubricants to be used under moderately elevated temperatures. Wheretemperatures in the order ,of. 400 Rand above are to be encountered,synthetic oils form a preferred class of lubricating bases because oftheir high .thermal stability. By the term synthetic oil The syntheticproperties of a hydrocarbon oil of lubricating grade suchasdi-Z-ethylhexyl sebacate, dioctyl phthalate and dioctyl azelate. Instead of an organic ester, we can use polymerized olefins, copolymers ofalkylene glycols and alkylene oxides, polyorgano siloxanes and the like.

' The liquid polyorgano siloxanes because of their exceedingly highthermal stability form a preferred group of synthetic oils to which thetetraphenylphthalyl compound and organophilic siliceous materials areadded. These llpolyorg ano siloxanes are known commercially as siliconesand are made up of silicon and oxygen atoms wherein the silicon atomsmay be substituted with alkyl, aryl,

alkaryl, aralkyl and cycloalkyl radicals. Exemplary of such compoundsare the dimethyl silicone polymers, di-

ethyl silicone polymers, ethyl-phenyl silicone polymers andmethyl-phenyl silicone polymers.

Ifdesired, a blend of oils of suitable viscosity may be employed as thelubricating oil base instead of a single oil by means of which anydesired viscosity may be secured. Therefore, depending upon theparticular use for which the ultimate composition is designed, thelubricating oil base may be a mineral oil, a synthetic oil, or a mixtureof mineral and/or synthetic oils. The lubricating oil content of thecompositions preparedaccording to this invention comprises about 40 toabout 90 percent by'weight of the total composition.

-In compounding the compositions of the present invention, variousmixing and blending procedures may be used. In a preferred embodiment ofthe invention, the lubricating oil, the tetraphenylphthalyl compound andthe secondary thickener together with a solvating agent and conventionallubricant additives, if desired, are mixed together at room temperature.for a period of to 30 "minutes to form a'slurry. During this initialmixing 'period some thickening is evidenced. Some lumps may be formed.The slurry thus formed is then subjected to a conventionalmillingoperation in a ball mill, a colloid mill, homogenizer or similardevice used in compounding greases to give the desired degree ofdispersion. In the illustrative compositions of this invention, theslurry was passed twice, by means of a pump, through a PremierfColloidMill set at a stator-rotor clearance of 0.002 inch. Maximu'm thickeningoccurred on the second pass through themill.

The lubricating composition of this invention can contain conventionallubricant additives, iffdesired, wiml'prove other specific properties ofthe lubricant without departing from the scope of the invention. Thus,the ',l'ub'r'i'cating composition, cancontain "a filler, a corrosion,rusflinhibitor,,an extreme pressure; agent, an antiioxida n t', .ametal deactivator, a? dye, and the "like. Whether er-nesuch'jiaidditives arT'ernployed'. and the amounts n'theseverity of'ndlto a, large extent the tetraphenylphthalyl 7 designed. Since many ofthe properties possessed by '10 sired elevated temperature which in thetests reported 8 the conditions to which the composition is subjectedand upon thestability of the lubricating oil base in the first instance.'Since thepolyorgano siloxanes, for example,

i are in general more stable than mineral oils, theyrequire theadditionof very little, if any, oxidation inhibitor.

When such'conventional additives are used theyv are generally added inamounts between about 0:01 and 5 percent by weight'based on the weightof the total composition. y M -In order to illustrate the lubricatingcharacteristics at an elevated temperature andhigh rotational speeds,grease compositions of the invention were subjectedto the test procedureoutlined by the Coordinating Research Council Tentative Draft (July,1954), Research Techniquefor the. Determination of PerformanceCharacteristics of Lubricating Grease in Antifriction BearingsatElevated Temperatures, CRC Designation L-35. According. to

this procedure, 3 grams of the grease. to be tested are "placed'in. abearing assembly containing an eight-ball which the test bearingassemblyis located is encased in a thermostatically controlled oven; Bythis means the temperature of the bearing can be maintained at adefhereinafter was 400? F. The spindle is driven by a constantbelt-tension motor drive assemb y, capableof giving spindle speeds up to10,000 revolutions per minute. The spindle-is operated on a cyclingschedule consisting of 1a"series of. periods, each period consisting of20 'hours running time and 4 hours shutdown time. The

test continues until the lubricant fails. The-lubricant is considered tohave failed when any one of the followingconditions occurs, (1) spindleinput power increases to a value approximately 300 percent above thesteady .state condition atfthe test temperature; (2) an increase in'temperature at the test bearing of 20 F. over the test temperatureduring any portion of a cycle; or (3) the test bearing locksor the drivebelt slips at the starter during the test cycle.

summarized in Table I were synthetic oils known commerically as GESilicon 81717 and DC 550 Fluid. GE

'Silicone, 81717 is marketed by General Electric Company and is awater-white the general formula I 3 2 3 K 3 2 3 )2 l x It has'aviscosity at "-65 FQof 3487 centistokes, at 0 F. of 390 centistokes, atF. of 71.3 centistokes, at 210? F. of 22 centistokes and at 700 F. of1.9 centistokes. DC 550 Fluid is marketed by Dow-Corningcorporationandis" a methylphenyl-siloxane polymer having as typicalcharacteristics a viscosity at 100 F. of 300 to :400 SUS, .aviscosity-temperature coefiicientof 0.75, a freezing point of --54 F., aflash point of 600 and a specific gravity 25 C./25 C. of 1.08. y TheEster'sil GT employed is marketed by E.I. du Pont de;Nemours and Companyand consists of an amorphous silica coated with approximately 340 butoxygroups per 100 square millimicrons' of surface. The productzis a .Whitegranular solidjcompris ing. 88 to 89 percent SiQ having an ultimateparticle sizeof 8 to 10 millimicrons.

The surface ;area :comp'rises about 285- to 335 ;square imet'ers pergram. The product has a pH in a]505 0 methanol-water mixture of 8.0 to9.0 and a bulk density fIr'i preparing the lubricating compositions, the

hthalyl compound and the di' th'y'ldicetylentonite or estersil weren'tixe atiqr'n' cmto amber liquid polymer of 9 peratu're for aperiodof'lll to 30 minutes. The slurry thus formed was passed twicethrough a Premier Colloid Mill set at a stator-rotor clearance of 0.002inch. The thickened lubricating compositions thus prepared had thefollowing approximate make-up".

TABLE 1 10 where Af-is selected from the group consisting of OR, OM andNRR Where M is an alkali metal and R and R are selected from thegroupconsisting of hydrogen and aliphatic, alicyclic and aromatichydrocarbon radicals having from 1 to 22 carbon atoms; inonoesters oftetraphenyl- Composition, Percent By Weight A Lubricating on:

on Silicone 81717 DC 550 Fluid Tetraphenylphthalyl Compound:

'letraphenylphthalie ,anhydride.

Disodium tetraphenylphth'tlam Meth f N-n-octadecyltetraphenylphthalmun PMono lsoo cytyl 'tetraphenyiphthalate.

Mono-u-hexyl tetranhenvlnhthalmn Secondary Thickener:

Dimethyldicetylammonium bentonite Estersil GT. i j Ratio oftetraphenylphthalyl compound to secondary thickener Inspection: U i HPeErformance Lite,lHrs -10,000 r.p.m.;at 400 i The long performance lifeof the compositions of the invention at a high rotational speed and ahigh tempera-" ture is self evident from the above data. Otherlubricating compositionsyvithinthe scope of the invention areillustrated in Table II. t

phthalic acid and alkali metal salts of monoesters oftetraphenylphthalic acid having the formula TABLE 2' Composition,:Percent-By Weight Di-2-ethylhexy1 sebar-m Tetraphenylphthalyl Compound;

N,N-dimethy1 tetraphenylphthalamate;; t

' Sodium N-octadecyltetraphenylphthalama 7 Sodium mono-dodccyltetraphenylphthalate Mono-cyclohexyi tetraphenylphthalate SecondaryThickener: L

Dimethyldicetylammonium tientnntt I "DimethyldidodecylammbniumbntoniteDimethyldioctylammon urn bentonite Dimethyldidctadecylam'rfnoiiiumbentonlte EstersilGT 1 Ratio of tetraphenylphthalyl compound tosecondary thickener 8:1 4:1 4:1

While our invention has been described with reference to variousspecific examples and embodiments, it will be understood that theinvention is not limited to such examples and embodiments and may bevariously practiced within the scope of the claims hereinafter made.

We claim:

1. A lubricating -corn'r' aosition comprising a dispersion:

in a lubricating oil era suflicie'nt amount to thicken the lubricatingoil to. a gfa'se' cdnsistency of a mixture of a tetraphenylphthalym'poundisel ected from the group consisting of "tetraph 'ylphthalicacidfand derivatives thereofsle'cted fro amates and alkali metal saltsof mono tetraphenylphthalamates having the formulai a iooNan p the groupconsisting of tetraphenylphthalic anhydr id'eymono and di-alkali metalsalts of "tetraphenylphthalic acid;"m'onoand 'di-tetraphenylphthalwhere.X iss'lected from the group consisting of hydrogen and an alkali metaland R", isfselected from the group consisting of aliphatic, alicyc'licand aromatic hydrocanbon radicals having from 1 to 22 carbon atoms; andimides of tetraphenylphthalic acid having the formula where R isselected from the group consisting of hydrogen and aliphatic, alicyclicand aromatic hydrocarbon radicals having from 1 to 22 carbon atoms; andan organophilic siliceous oil uthickening iagent, the weight ratio ofthe ,tetraphenylphthalyl COIIIPOIlIldxtO the organophilic siliceousmaterial in said mixture being about 1:71 to labout 50:11.

75 2. ';I?he :lubricating composition of claim 1 wherein the 5. Thelubricating composition of claim 1 wherein the organophilic siliceousoil thickening agent is an organophilic esters'il comprising asupercolloidal substrate coated with --OR' groups, the substrate havinga surface of silica 6. A lubricating composition comprising a dispersionin lubricating oil. to a grease consistency of a mixture of atetraphenylphthalamate, having the formula:

GOA

and having a specific surface area of from 1 to 900'sqi1areI areSelected from group conslstmg of hydrogen and meters per gram, thecoating of -'OR' groupsbeing chemaliphatic, alicyclic and aromatichydrocarbon radicals having from late 22 carbonatoms and an organophilicsiliceous oil thickening agent, the weight ratio of thetetraphenylphthalamateito the organophilic siliceous material in ,saidmixture being about 1:1 to about50:l.'

a liquid polyorgano silox-ane of a sufficient. amount to thicken thepolyorgano siloxane to a greaseconsistency of a mixture of atetraphenylphthalyl compound selected from the group consisting oftetraphenylphthalic acid and derivatives thereof selected from the groupconsisting of tetraphenylphthalic anhydride; monoand di-alk-ali metal;

8. The lubricating composition of claim 7 wherein thetetraphenylphthalamate' is methyl N-n-octadecyltetra-'phenylphthalamate. t a

9. A lubricating composition comprising a dispersion in a lubricatingoil of a sufficient amount to thicken the lubricating where A isselected from the group consisting of OR, 0M1; and NRR' where M is analkali metal and R and R,

are selected from the group consisting of hydrogen and aliphatic,alicyclic and aromatic hydrocarbon radicals having from 1 to 22 carbonatoms; monoesters of tetraphenylphthalic acid and alkali metal salts ofmonoester of tetraphenylphthalic acid having the formula a coox oil to agrease consistency of a mixture of a tetraphenylphthalate havingtheformula:

COOK "whr'exis selected fromlthe'group consisting of hydroradicalshaving from 1 to 22 carbon atoms and an organophilic siliceous oilthickening agent, the weight ratio of the tetraphenylphthalate: to theorganophilic siliceous 11. The lubricating composition of claim9 whereinthe tetraphenylphthalate is mono-n-hexyl tetraphenylj phthalate.

12, A lubricating composition comprising a dispersion f in a lubricatingoil ofa sufiicient amount to thicken the lubricating oil to a greaseconsistency of a mixture of a t E t t 7 5 where X is selected from thegroupconsisting of hydroand. a iphatic, alicyclic and; aI-Q flhydrogiarbon radicals h vin rom '1 tozz carbo tatougs a a .v o p i 1 s;oil thicke ngiagcnmth we ratio of h tetraphenylphthalimide:itotheorganophilic siliceous mawhere R is selected from the groupconsisting of hydrogen 7 and aliphatic,.alicyclic and aromatichydrocarbon radicals havingfrom 1;;to,22 carbon atoms; and anorganophilic tbentonite-organic, base compound; the. weight ratioOfIhCg' al'lubr'icating' oil of a sufficient amount to thickfiitl thetetraphenylphthalimide having the formula:

where Ris selected from-thegroup consisting of hydrogen 'terial -insaid-mixture b,eing-,abouti'1:1 to about 50: 1 q 13.Aglubricatingcomposition comprising a, dispersion in' a liguidpolyo'rgano siloxanejof ;a sufiicient amount to thicken thepolyorgari'o; siloxanewto= a grease consistency of a mixture of atetraphenylphthalylcompound selected from the group consisting oftetraphenylphthalic acid and derivatives thereof selected from the groupconsisting of the anhydride, mono 'an'ddialkali metal salts, monoanddi-amides, alkali metal salts of mbnoamides, monoesters, alkali metalsalts of monoesters and imides and an organophilic estersil, the weightratio of the tetraphenylphthalyl compound to the organophilic estersilin said mixture being about 1:1 to about 50:1, said organophilicestersil compn'sing a supercolloidal substrate coated with -OR' groups,the substrate having a surface of silica and having a specific surfacearea of from 25 to 900 square meters per gram, the coating of OR groupsbeing chemically bound to said silica and R being a hydrocarbon radicalof from 3 to 6 carbon atoms, wherein the carbon atom attached to oxygenis also attached to hydrogen.

14. The lubricating composition of claim 13 wherein thetetraphenylphthalyl compound is methylN-n-octadecyltetraphenylphthalamate and the organophilic estersil is anamorphous silica coated with about 340 butoxy groups per 100 squaremillimicrons of surface.

References Cited in the file of this patent UNITED STATES PATENTS2,578,851 Smith et a1. Dec. 18, 1951 2,710,839 Swakon et al June 14,1955 2,756,213 Dixon July 24, 1956 2,766,209 Marshall et a1. Oct. 9,1956 2,806,877 Koenecke et al Sept. 17, 1957 2,820,012 Hotten Jan. 14,1958 UNITED STATES PATENT OFFICE Certificate of Correction P t I ene.2,983,682 May 9,1961

Robert E. Halter et a1.

It ;is hereby certified that error appears in the above numbered patentrequiring correction and that the sald Letters Patent should read ascorrected below.

Column 1, line 57, for anhydried read anl1ydride compiund read compound;column 6, line 30, for prowc dp6wdens column 9, Table 1, first columnthereof, eighth item, for Mono-isoocytyl read -Mono is00ctyl; same tableand same column, third line from the bottom, for (ASTM 135566-42) read(ASTM D566- 12); column 12, line '72, beginning with the anhydride,monoand strike out all to and including imides in line 74, same column,and insert instead the following: -tetraphenylphthalic anhydride;monoand di-alkali metal salts of tetraphenylphthalic acid; monoanddi-tetraphenylphthalamates and alkali metal salts ofmono-tetraphenylohthalamates having the formula where A is selected fromthe group consisting of OR, OM and NRR where M is an alkali metal and Rand R are selected from the group consisting of hydrogen and aliphatic,alicyclic and aromatic hydrocarbon radicals having from 1 to 22 carbonatoms; monoesters of tetraphenylphthalic acid and alkali metal salts ofmonoesters of tetraphenylphthalic acid having the formula COOX COORwhere X is selected from the group consisting of hydrogen and an alkalimetal and R" is selected from the group consisting of aliphatic,alicyclic and aromatic hydrocarbon radicals having from 1 to 22 carbonatoms; and imides of tetraphenylphthalic acid having the formula where Ris selected from the group consisting of hydrogen and aliphatic,alicyclic and aromatic hydrocarbon radicals having from 1 to 22 carbonatoms Signed and sealed this 10th day of October 1961.

Attest: ERNEST W. SWIDER, Attest'i'ng Ofiicer.

DAVID L. LADD, Gammz'ssionw of Patents.

1. A LUBRICATING COMPOSITION COMPRISING A DISPERSION IN A LUBRICATINGOIL OF A SUFFICIENT AMOUNT TO THICKEN THE LUBRICATING OIL TO A GREASECONSISTENCY OF A MIXTURE OF A TETRAPHENYLPHTHALYL COMPOUND SELECTED FROMTHE GROUP CONSISTING OF TETRAPHENYLPHTHALIC ACID AND DERIVATIVES THEREOFSELECTED FROM THE GROUP CONSISTING OF TETRAPHENYLPHTHALIC ANHYDRIDE,MONO- AND DI-TETRAPHENYLPHTHALTETRAPHENYLPHTHALIC ACID, MONO- ANDDI-TETRAPHENYLPHTHALAMATES AND ALKALI METAL SALTS OFMONO-TETRAPHENYLPHTHALAMATES HAVING THE FORMULA